Field of the Invention
The present invention relates to an image processing apparatus and an image processing method and, more particularly, to an image processing apparatus and an image processing method in which a RAW image of a moving image is handled.
Description of the Related Art
In an imaging device in the related arts, raw image information (RAW image) photographed by an imaging sensor is deBayer processed (demosaic processed) and converted into a luminance signal and color difference signals and, thereafter, what is called a developing process such as noise elimination, optical distortion correction, image optimization, and the like is executed with respect to each signal. Generally, the development processed luminance signal and color difference signals are compression encoded and recorded into a recording medium.
On the other hand, an imaging device which can record a RAW image also exists. As for the RAW image, although an amount of data necessary to record is extremely large, since there is such an advantage that an original image can be edited after the photographing while suppressing deterioration to the original image to a minimum limit, the RAW image is intentionally used by a high-ranking person.
In recent years, in association with a high processing speed of an image processing circuit and a large storing capacity of a recording medium, an imaging device which simultaneously records both of compression encoded image data and RAW image data has also been proposed. In such an imaging device which can simultaneously record the data, the compression encoded image data of a small data amount is handled as proxy data, the RAW image data serving as a main image is not directly accessed, and functions such as designation of start and end positions of a scene on the proxy data, output to a sub-screen, and the like are realized. In this manner, the compression encoded image data is used in an application for realizing simplicity and a high processing speed of an editing work after the photographing.
On the other hand, such a still image capture function that during the reproduction of compression encoded moving image data after the recording, only an arbitrary image frame designated by the user is extracted and stored and recorded separately from the moving image data as a printable still image data format such as JPEG or the like has been proposed. However, since a screen size of a still image suitable for a print application is larger than a screen size of a moving image and a picture quality is also deteriorated due to the compression encoding, a still image of a high quality cannot be always obtained.
Japanese Patent Application Laid-Open No. 2005-286612 discloses such a unit that interpolation pixels are generated by using a frame image in print designated moving image data and reference frame images of the frame image and a synthesis image of a larger screen size is obtained.
However, according to the method whereby after the compression encoded moving image data was decoded, a plurality of reference frame images are held and synthesized as disclosed in Japanese Patent Application Laid-Open No. 2005-286612, in the case of an image in which there are many motions of an object to be photographed or an image in which a scene change occurs, a correlation between the reference frame images and the decoded image is low. Therefore, a still image of a high picture quality cannot be always obtained.
According to the construction of the imaging device which can simultaneously record the RAW image data and the compression encoded moving image data, by developing the RAW image data without a deterioration in picture quality after that, the still image of a high quality can be obtained. However, according to such a method, in order to designate the extracting position of the still image, since it is necessary to temporarily stop the reproduction of the proxy moving image each time and execute the developing process of the RAW image, there is such a risk that a complexity of the user operation is caused and a working load increases.